Method of obtaining carotene from palm oil



Patented Sept. 15, 1953 METHOD OF OBTAINING CAROTENE FROM PALM OILPierre Blaizot, Paris, France, assignor to Institut de Recherches pourles Huiles de Palmeet Oleagineux, Paris, France No Drawing. ApplicationOctober 8, 1949, Serial No. 120,417. In France February 10, 1949 1Claim. 1

Palm oil is a mixture of mixed or homogeneous glycerides (i. e. estersof glycerine) in which a small amount of unsaponifiables are present insolution which mainly consist of isomeric carotenes beside carotene-likepigments and sterols. An oil of African origin will contain about 1 gramof carotene per kilogram.

It is Well known to separate the oil, irrespective of its acid value,into two fractions, either by crystallization at 15-16 C., or by theaction of selective solvents, by hydro-extraction, pressfiltering orcentrifuging or any other mechanical method. One of the said fractionsis solid up to a temperature of 30 to 49 C. and represents about of theweight of palm oil treated. Said fraction is light in color, which meansthat very little carotene-like pigments are retained therein. Aftercomplete neutralization, deodorization and bleaching a vegetable fat isobtained which can be used either directly for cooking purposes oradvantageously in the manufacture of margarine.

The second fraction is fluid at temperatures higher than 17 C. andrepresents about of the weight of the initial oil. It has a decided deepred color owing to the presence of the bulk of the carotene-likepigments present in the palm oil. It consists mainly of mixed glyceridesof palmitic, linoleic, and above all, oleic acids.

The neutralization of the free acids in the palm oil may be carried outeither before or after the fractionation.

The last-mentioned glyceride-containing fraction may be subjected to theconventional reaction Well known as alcoholysis. The glycerides areconverted thereby into esters of a lowermolecular alcohol in thepresence of an acid or an alkaline catalyst. In the case of red oil,sodium or potassium hydroxide is used. With a yield of at least 95%there are obtained palmitates, oleates and linoleates of the alcoholused while glycerine is separated. Where the liquid fractions of the oilare used the ester mixture will contain about 70% of oleate.

A glycerine is decanted which is comparatively concentrated. The residueis washed with water until neutral and the excess alcohol may berecovered by distillation.

The methyl esters (which are strongly colored red by the carotene) arethen treated for extraction of the pigment.

My invention consists in saponifying esters of low-molecular alcoholswith a strong alkali in alcohol. The process should be carried out at nomore than C. and in a nitrogen atmosphere. The soap is dried in a vacuumand extracted with an organic solvent such as petroleum ether or achloro-derivative thereof by which the carotenes are dissolved. Bydistilling off the solvent a residue is obtained which consists of theunsaponifiable portion of the palm oil. In the case of the liquidfraction of palm oil, the extraction is facilitated considerably by thefact that a much smaller amount of soap has to be treated whichcorresponds but to one third of the weight of the initial palm oil.

To the solution obtained there may be added a controlled amount e. g. ofa liquid vegetable oil such as colza-, oliveor peanut oil, the solventthen being driven oif on a hot water bath. An oily carotene preparationremains which is particularly suitable for alimentary or therapeuticpurposes.

Example.100 kgs. of raw palm oil having an acid value of 10% areneutralized with sodium hydroxide. About kgs. of neutral oil areobtained which are subjected to fractional crystallization at about 15C. By filter-pressing there are obtained 50 kgs. of a concrete fat whichis light in color and besides 30 kgs. of a liquid red oil.

To 30 kgs. of red oil there are added 7 to 10 kgs. of concentratedmethyl alcohol containing 1 to 3% of alkali hydroxide. The mixture isagitated for 3 hours at surrounding temperature. About 2 kgs. ofhigh-percentage glycerine separate out which are removed by decanting.

To the 30 kgs. of red esters thus obtained there are added 14 kgs. of 36B. soda lye, the operation being carried out in a nitrogen atmosphereand care being taken that the temperature remains below 60 C. The saidtemperature is maintained for 3 hours while agitating mechanically andthe whole product is dried in a vacuum under continued agitation.

The soap is then extracted with about 50 litres of petroleum ether orchloroform until same is bleached as much as possible, after which 1 to2 kgs. of colza, or olive, or peanut oil are added. The petroleum etheris distilled off and an oily carotene-containing residue is obtained inwhich the carotene-content is about 3%, more or less depending on thepercentage of the same in the initial palm oil.

What I claim is:

In a method of producing carotene from palm oil, the steps which consistin successively separating the oil into a solid fraction and a liquid '4car0tene-rich fraction, alcoholyzing the latter to Number esters oflow-molecular alcohols, sa-ponifying said 2,432,181 esters with a strongalkali under a vacuum and 2,440,029 extracting the resulting soap withan organic 2,460,796 solvent. 5

PIERRE BLAIZOT.

Number References Cited in the file of this patent 5 5,095

UNITED STATES PATENTS Number Name Date 10 2,032,006 Cross Feb. 25, 19362,318,747 Buxton May 11, 1943 May 11' 1943 2,432,021 Lerner Dec. 2, 1947Name Date Trent Dec. 7, 1947 Tabor Apr. 20, 1948 Eckey Feb. 1, 1949FOREIGN PATENTS Country Date Great Britain Oct. 26, 1944 OTHERREFERENCES Buckley: Chem. Abs. (1935), col. 7105. Ser. No. 414,980,Grandel (A. P. 0.), published

